Electric valve

Abstract

A valve port forming member (50) that forms a valve port (52a) through which a fluid passes; a valve body (48) that opens and closes the valve port; a magnetic gear (60b) that magnetically transmits rotational power from an output shaft (14) of the motor unit to the valve body; and a control unit (81) that controls the current supplied to the motor unit. When a full-closing operation in which the valve port is fully closed by the valve body is performed, the control unit limits the current supplied to the motor unit to a full-closing-time limit current value (Is) or less, and the full-closing-time limit current value is a current value greater than an opening-degree-adjustment-time current value (Ia). The current value during opening degree adjustment is the value of the current supplied to the motor unit during opening degree adjustment in which the opening degree of the valve port is adjusted by the valve body.

Description

[0001] Cross-reference to related applications

[0002] This application is based on Japanese Patent Application No. 2022-101834 filed on June 24, 2022, and the contents thereof are incorporated herein by reference. Technical Field

[0003] The present invention relates to an electric valve which is driven to open and close by an electric motor. Background Art

[0004] Conventionally, such an electric valve is described in Patent Document 1. In this prior art, an electric motor drives a main valve body to seat the main valve body on a main valve seat, thereby achieving a closed valve state in which a main valve port is closed.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2020-34140

[0008] In an electric valve, in order to prevent the fluid for flow regulation from entering the electric motor, the fluid must be well sealed. As a countermeasure, a magnetic gear that magnetically transmits the rotational driving force is considered to be used in a transmission mechanism that transmits the rotational driving force from the electric motor to the valve element.

[0009] However, in this countermeasure, when the torque of the electric motor exceeds the torque that causes the magnetic gear to lose its adjustment, the magnetic gear loses its adjustment and repeatedly rotates forward and reverse, so that the valve cannot be closed reliably, and fluid leakage occurs. Summary of the invention

[0010] In view of the above-mentioned points, an object of the present invention is to reduce fluid leakage when the valve is fully closed in an electric valve having a magnetic gear.

[0011] An electric valve according to one aspect of the present invention includes a motor unit, a valve port forming member, a valve element, a magnetic gear, and a control unit.

[0012] The motor unit generates a rotational driving force by being supplied with electric power. The valve port forming component forms a valve port through which a fluid passes. The valve core opens and closes the valve port. The magnetic gear magnetically transmits the rotational driving force from the output shaft of the motor unit to the valve core. The control unit controls the current supplied to the motor unit.

[0013] When the valve core is fully closed to fully close the valve port, the control unit limits the current supplied to the motor unit to a value less than the fully closed limit current value. The fully closed limit current value is a current value greater than the current value during the opening adjustment. The current value during the opening adjustment is the value of the current supplied to the motor unit during the opening adjustment to adjust the opening of the valve port through the valve core.

[0014] This can prevent the current supplied to the motor from being excessive during the full closing operation, which can cause the magnetic gear to become out of step. Therefore, since the valve body can be prevented from reversing due to the out of step of the magnetic gear, the full closing property of the valve port can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above-mentioned object and other objects, features and advantages of the present invention will become more apparent through the following detailed description made with reference to the accompanying drawings.

[0016] Figure 1 It is a diagram showing the overall configuration of a vehicle air conditioning device according to the first embodiment.

[0017] Figure 2 It is a cross-sectional view showing the first expansion valve according to the first embodiment.

[0018] Figure 3 yes Figure 2 III-III cross-sectional view.

[0019] Figure 4 1 is a block diagram showing an electronic control unit of the vehicle air conditioning system according to the first embodiment.

[0020] Figure 5 This is a graph showing the relationship between torque and current in the motor portion of the first expansion valve according to the first embodiment.

[0021] Figure 6 This is a graph for explaining the failure detection current value and the fully closed limit current value stored in the first expansion valve control device of the first embodiment.

[0022] Figure 7 This is a flowchart showing a control process executed by the first expansion valve control device according to the first embodiment.

[0023] Figure 8 This is a graph for explaining the failure detection current value and the fully closed limit current value stored in the first expansion valve control device according to the second embodiment.

[0024] Fig. 9 This is a graph for explaining the failure detection current value and the fully closed limit current value stored in the first expansion valve control device according to the third embodiment.

[0025] Fig.10This is a graph for explaining the failure detection current value and the fully closed limit current value stored in the first expansion valve control device according to the fourth embodiment.

[0026] Fig.11 This is a flowchart showing a control process executed by the first expansion valve control device according to the fifth embodiment.

[0027] Fig.12 This is a flowchart showing a control process executed by the first expansion valve control device according to the sixth embodiment. DETAILED DESCRIPTION

[0028] Hereinafter, multiple forms for implementing the present invention will be described with reference to the accompanying drawings. For parts in each embodiment corresponding to matters described in the previous embodiment, the same reference symbols are sometimes given and repeated descriptions are omitted. In the case where only a part of the structure is described in each embodiment, other embodiments previously described can also be applied to other parts of the structure. Not only can the parts that are specifically and clearly indicated as being combinable in each embodiment be combined with each other, but as long as there is no particular obstacle to the combination, the embodiments can be partially combined with each other even if it is not clearly indicated.

[0029] (First Embodiment)

[0030] For the first embodiment of the present invention, refer to Figure 1 to Figure 7 The power transmission device 1 of this embodiment is applicable to the first expansion valve 113 and the second expansion valve 115 of the vapor compression refrigeration cycle 110. The vapor compression refrigeration cycle 110 is applicable to Figure 1 The vehicle air conditioner 100 is shown. The vehicle air conditioner 100 is suitable for an electric vehicle that obtains a driving force for traveling the vehicle from an electric motor for traveling.

[0031] The vehicle air conditioner 100 has three operation modes: a cooling mode for cooling the vehicle interior, a heating mode for heating the vehicle interior, and a dehumidification and heating mode for heating the vehicle interior while dehumidifying the vehicle interior. Figure 1 In the figure, the refrigerant flow in the cooling mode is represented by a solid arrow, the refrigerant flow in the heating mode is represented by a dotted arrow, and the refrigerant flow in the dehumidification heating mode is represented by a double-dashed arrow.

[0032] The vehicle air conditioning device 100 includes a vapor compression refrigeration cycle 110 and a vehicle interior air conditioning unit 120 .

[0033] The vapor compression refrigeration cycle 110 includes a compressor 111 , an indoor heat exchanger 112 , a first expansion valve 113 , an outdoor heat exchanger 114 , a second expansion valve 115 , an evaporator 116 , an electromagnetic on-off valve 117 , and an accumulator 118 .

[0034] The compressor 111 is an electric compressor that sucks, compresses, and discharges refrigerant. The vapor compression refrigeration cycle 110 is a subcritical cycle in which the refrigerant pressure on the high-pressure side does not exceed the critical pressure of the refrigerant, and a Freon series refrigerant (eg, R134a) is used as the refrigerant circulating in the vapor compression refrigeration cycle 110.

[0035] The indoor heat exchanger 112 condenses the refrigerant discharged from the compressor 111 by exchanging heat with the air flowing in the vehicle interior air conditioning unit 120. The first expansion valve 113 decompresses and expands the refrigerant condensed in the indoor heat exchanger 112. The outdoor heat exchanger 114 exchanges heat between the refrigerant flowing out of the first expansion valve 113 and the outside air.

[0036] The second expansion valve 115 decompresses and expands the refrigerant flowing out of the outdoor heat exchanger 114. The evaporator 116 evaporates the refrigerant decompressed and expanded by the second expansion valve 115 by exchanging heat with air flowing in the vehicle interior air conditioning unit 120.

[0037] The electromagnetic on-off valve 117 is an electromagnetic valve that opens and closes the refrigerant flow path that allows the refrigerant flowing out of the outdoor heat exchanger 114 to bypass the second expansion valve 115 and the evaporator 116 and guide to the accumulator 118. The accumulator 118 separates the refrigerant evaporated in the evaporator 116 from the gas and liquid of the refrigerant passing through the electromagnetic on-off valve 117.

[0038] The vehicle interior air conditioning unit 120 is disposed in the vehicle interior and forms an air passage therein. In the air passage in the vehicle interior air conditioning unit 120, a blower 121, an evaporator 116, an indoor heat exchanger 112, and an air mix door 122 are disposed.

[0039] The blower 121 is an electric blower that blows air into the air passage in the vehicle interior air conditioning unit 120. The evaporator 116 is arranged downstream of the air flow relative to the blower 121. The indoor heat exchanger 112 is arranged downstream of the air flow relative to the evaporator 116. The air mixing door 122 adjusts the flow rate ratio of the air flowing into the indoor heat exchanger 112 and the air flowing bypassing the indoor heat exchanger 112. The vehicle interior air conditioning unit 120 blows the air whose temperature is adjusted by the air mixing door 122 into the vehicle interior.

[0040] In the cooling mode of the vehicle air conditioner 100, the electromagnetic on-off valve 117 is in a closed valve state, and the air mix door 122 blocks the air flow path to the indoor heat exchanger 112. Therefore, the refrigerant discharged from the compressor 111 does not perform heat exchange in the indoor heat exchanger 112 but passes through the indoor heat exchanger 112, flows in the order of the first expansion valve 113, the outdoor heat exchanger 114, the second expansion valve 115, the evaporator 116, and the accumulator 118, and returns to the compressor 111 from the accumulator 118.

[0041] At this time, the first expansion valve 113 is in a fully open state without throttling the flow of the refrigerant, and the second expansion valve 115 is in a valve opening degree that throttles the flow of the refrigerant. Therefore, the refrigerant condenses in the outdoor heat exchanger 114 and evaporates in the evaporator 116.

[0042] In the heating mode of the vehicle air conditioner 100, the electromagnetic on-off valve 117 is in an open valve state, the second expansion valve 115 is in a closed valve state to block the flow of refrigerant, and the air mix door 122 is opened to allow air to flow to the indoor heat exchanger 112. Therefore, the refrigerant discharged from the compressor 111 flows in the order of the indoor heat exchanger 112, the first expansion valve 113, the outdoor heat exchanger 114, the electromagnetic on-off valve 117, and the accumulator 118, and returns to the compressor 111 from the accumulator 118. At this time, the first expansion valve 113 is in a valve opening degree to throttle the flow of refrigerant, and the second expansion valve 115 is in a closed valve state, so that the refrigerant condenses in the indoor heat exchanger 112, the refrigerant evaporates in the outdoor heat exchanger 114, and the refrigerant does not flow in the evaporator 116.

[0043] In the dehumidification and heating mode of the vehicle air conditioner 100, the electromagnetic on-off valve 117 is in a closed state, and the air mix door 122 is opened to allow air to flow to the indoor heat exchanger 112. Therefore, the refrigerant discharged from the compressor 111 flows in the order of the indoor heat exchanger 112, the first expansion valve 113, the outdoor heat exchanger 114, the second expansion valve 115, the evaporator 116, and the accumulator 118, and returns to the compressor 111 from the accumulator 118.

[0044] At this time, the first expansion valve 113 and the second expansion valve 115 are at valve openings that throttle the flow of the refrigerant, so that the refrigerant condenses in the indoor heat exchanger 112 and evaporates in the outdoor heat exchanger 114 and the evaporator 116 .

[0045] like Figure 2 As shown, the first expansion valve 113 has a power transmission device 1, a driving side mechanism 10 and a driven side mechanism 35. The first expansion valve 113 is arranged longitudinally on the vehicle. The longitudinal arrangement means that the axial direction of the valve core 48 is roughly parallel to the vertical direction of the vehicle, and the driving side mechanism 10 is located on the upper side of the vehicle relative to the driven side mechanism 35.

[0046] The power transmission device 1 transmits the rotational driving force generated by the driving-side mechanism portion 10 to the driven-side mechanism portion 35 by using magnetic force.

[0047] The driving side mechanism 10 includes a motor 11 and a motor case 15. The motor 11 is a motor that can be driven by speed feedback control and includes a stator 12, a rotor 13, and a shaft 14. The motor 11 is, for example, a three-phase brushless motor or a DC brush motor.

[0048] The shaft 14 is an output shaft of the motor unit 11 and an input shaft of the power transmission device 1, and rotates integrally with the rotor 13. The motor housing 15 accommodates the motor unit 11.

[0049] The stator 12 is fixed to the motor case 15. The stator 12 has a stator coil 12a. In this example, the number of slots Ns of the stator 12 is six.

[0050] The rotor 13 is cylindrical, and the stator 12 is arranged inside the rotor 13. Figure 3 As shown, the rotor 13 is provided with a plurality of pairs of magnets consisting of N poles 13n and S poles 13s in the circumferential direction. In this example, there are four N poles 13n and four S poles 13s, respectively, so the number of poles Pr of the rotor 13 is 8. The stator 12 and the rotor 13 output a driving force for rotating the shaft 14 through electromagnetic force.

[0051] The motor housing 15 is provided with an aligning portion 15a for aligning (centering) the shaft 14 of the driving-side mechanism portion 10 and the rotating member 41 of the driven-side mechanism portion 35. The aligning portion 15a is fitted with the main body portion 50 of the driven-side mechanism portion 35.

[0052] The electric circuit unit 70 is housed in the motor case 15 . The electric circuit unit 70 includes a circuit board on which a plurality of electronic components for controlling the motor unit 11 are mounted.

[0053] The driven side mechanism 35 includes a rotating member 41, a valve core 48, a bearing member 49, and a main body 50. The rotating member 41, the valve core 48, and the bearing member 49 are accommodated in the main body 50. The main body 50 constitutes a frame of the first expansion valve 113 together with the motor housing 15. A valve chamber 52, an inlet side connection port 53, an outlet side connection port 54, and a valve seat 55 are formed in the main body 50. The main body 50 is a valve port forming member that forms a valve port 52a of the valve chamber 52.

[0054] The rotating member 41 is an output shaft of the power transmission device 1, and is rotated by the driving force transmitted from the driving side mechanism portion 10. The rotating member 41 is a rod-shaped member, and is arranged coaxially with the shaft 14. An engagement groove 41a is formed at the end of the rotating member 41 on the opposite side of the driving side mechanism portion 10. The rotating member 41 is supported by a bearing member 49 fixed to the main body portion 50 so as to be rotatable.

[0055] The valve element 48 is a rod-shaped member disposed in the valve chamber 52. The valve element 48 is disposed coaxially with the rotating member 41. The protruding piece 48a of the valve element 48 meshes with the meshing groove 41a of the rotating member 41. Thus, the rotational force of the rotating member 41 is transmitted to the valve element 48.

[0056] The protruding piece 48a is formed at one end of the valve core 48. An external thread is formed on the outer peripheral surface of the valve core 48. The external thread of the valve core 48 is screwed into a screw hole 50a formed in the main body 50 to form a screw mechanism. As a result, when the valve core 48 rotates, the valve core 48 moves in the axial direction.

[0057] The valve core 48 is formed of a plurality of parts. Specifically, the valve core 48 is composed of an external threaded part 481 located on the rotating part 41 side and forming the external thread, a valve seat side part 482 located on the valve seat 55 side, and a ball 483 disposed between the two parts 481 and 482. By disposing the ball 483 between the two parts 481 and 482, the valve seat side part 482 in the valve core 48 does not rotate but moves in the axial direction.

[0058] The valve seat side member 482 serving as the ball seat member of the valve body 48 is urged by the coil spring 47 toward the side of the valve body 48 that is away from the valve seat 55 in the axial direction.

[0059] The valve core 48 moves axially so that the valve core 48 abuts against or leaves the valve seat 55, thereby opening and closing the valve port 52a of the valve chamber 52. In the valve chamber 52, the valve core 48 leaves the valve seat 55, and the refrigerant flows from the inlet side connection port 53 to the outlet side connection port 54 through the valve port 52a to be decompressed and expanded.

[0060] The power transmission device 1 includes a non-contact coupling portion 60. The non-contact coupling portion 60 includes a magnetic gear 60b and a sealing plate 51. The magnetic gear 60b includes a driving side magnet 20, a magnetic pole piece 25, and a fixed magnet 40.

[0061] The driving side magnet 20 rotates integrally with the shaft 14 of the motor unit 11. The pole piece 25 modulates magnetic flux between the driving side magnet 20 and the fixed magnet 40 and rotates integrally with the rotating member 41. The fixed magnet 40 is fixed to the main body 50 of the first expansion valve 113.

[0062] The driving side magnet 20 is cylindrical and is joined to the outer peripheral surface of the rotor 13 of the motor unit 11 via a cylindrical interposer 21. That is, the motor unit 11 is arranged inside the driving side magnet 20. The interposer 21 is formed of a magnetic body.

[0063] The driving side magnet 20 includes at least one pair of magnets consisting of an N pole 20n and an S pole 20s arranged in the circumferential direction. In this example, there are one N pole 20n and one S pole 20s, so the number of poles Pin of the driving side magnet 20 is two.

[0064] The number of poles Pin of the driving side magnet 20 is equal to the value obtained by subtracting the number of slots Ns of the stator 12 from the number of poles Pr of the rotor 13. In this example, the number of poles Pr of the rotor 13 is 8, the number of slots Ns of the stator 12 is 6, and thus the number of poles Pin of the driving side magnet 20 is 2.

[0065] The sealing plate 51 is a sealing member that divides the internal space of the first expansion valve 113 into a driving side space 113a and a driven side space 113b and seals the driven side space 113b. The driving side space 113a is a space on the driving side mechanism unit 10 side, and the driven side space 113b is a space on the driven side mechanism unit 35 side.

[0066] The sealing plate 51 prevents the refrigerant (high-pressure refrigerant) in the driven-side space 113b from leaking into the driving-side space 113a. In this example, the sealing plate 51 is formed of a non-magnetic body (for example, SUS305).

[0067] The sealing plate 51 is in the shape of a disk with a center portion concave downward, and has a sealing upper surface portion 51a, a sealing cylindrical portion 51b, and a sealing bottom portion 51c. The sealing upper surface portion 51a is in the shape of an annular plate, and the outer edge portion is fixed to the main body portion 50 of the first expansion valve 113. The sealing cylindrical portion 51b is in the shape of a cylinder and is located on the outer diameter side of the driving side magnet 20. The sealing bottom portion 51c is located on the lower side of the driving side magnet 20 and blocks the sealing cylindrical portion 51b from the driving side space 113a side.

[0068] The sealing bottom surface portion 51c is in the shape of a disk with the center portion bent downward. The corner forming the boundary between the sealing cylindrical portion 51b and the sealing bottom surface portion 51c is not a right angle but is rounded with a predetermined radius of curvature, thereby improving pressure resistance.

[0069] The sealing plate 51 is formed by integrally forming a sealing upper surface portion 51 a , a sealing cylindrical portion 51 b , and a sealing bottom surface portion 51 c in order to improve pressure resistance.

[0070] The seal bottom surface portion 51c is disposed in the gap between the shaft 14 and the rotating member 41 in the axial direction of the shaft 14 and the rotating member 41. That is, the seal bottom surface portion 51c is disposed at a location where there are few torque generating points. Therefore, it is easy to ensure the torque resistance and pressure resistance of the seal plate 51.

[0071] The magnetic pole piece 25 has a cylindrical shape and is disposed on the outer diameter side of the sealing cylindrical portion 51b of the sealing plate 51. The magnetic pole piece 25 is joined to the rotating member 41 of the driven-side mechanism portion 35.

[0072] The fixed magnet 40 is cylindrical and is disposed on the outer diameter side of the magnetic pole piece 25. The fixed magnet 40 is embedded in the cylindrical main body cylinder 50b (in other words, the frame cylinder) in the main body 50 (in other words, the frame) via the cylindrical back yoke 56. The back yoke 56 and the main body cylinder 50b are formed of a magnetic body.

[0073] The fixed magnet 40 is provided with a plurality of pairs of magnets consisting of N poles 40n and S poles 40s at approximately equal intervals in the circumferential direction. The number of poles Pf of the fixed magnet 40 is greater than the number of poles Pin of the drive side magnet 20. In this example, there are 20 N poles 40n and 20 S poles 40s, so the number of poles Pf of the fixed magnet 40 is 40.

[0074] The magnetic pole piece 25 has a plurality of magnetic body parts 25a and a plurality of non-magnetic body parts 25b. The magnetic body parts 25a and the non-magnetic body parts 25b are in a fan-shaped trapezoidal shape, and the magnetic body parts 25a are arranged at approximately equal intervals along the circumferential direction. The non-magnetic body parts 25b are arranged between the magnetic body parts 25a. For example, the magnetic body parts 25a are formed of a soft magnetic body (such as an iron-based metal), and the non-magnetic body parts 25b are formed of a non-magnetic body (such as stainless steel or resin).

[0075] The number of poles Pp of the pole piece 25 is the same as the sum of the number of poles Pin of the drive side magnet 20 and the number of poles Pf of the fixed magnet 40. In this example, the number of poles Pin of the drive side magnet 20 is 2, and the number of poles Pf of the fixed magnet 40 is 40, so the number of poles Pp of the pole piece 25 is 42. That is, the number of magnetic body parts 25a and the number of non-magnetic body parts 25b are 21 each. That is, the number Npp of the magnetic body parts 25a relative to the number of poles Pin of the drive side magnet 20 and the number of poles Pf of the fixed magnet 40 is as follows:

[0076] Npp=(Pin+Pf) / 2

[0077] The axial length of the pole piece 25 is shorter than the axial length of the fixed magnet 40. This can reduce the magnetic flux leakage in the axial direction of the pole piece 25 and improve the transmission torque.

[0078] The configuration of the second expansion valve 115 is the same as that of the first expansion valve 113 , and thus a detailed description of the configuration of the second expansion valve 115 will be omitted.

[0079] Next, an overview of the electric control unit according to the present embodiment will be described. Figure 4The air conditioning control device 80, the first expansion valve control device 81, and the second expansion valve control device 82 shown are well-known microcomputers including a CPU, a ROM, a RAM, etc., and an electronic control unit having peripheral circuits. The air conditioning control device 80, the first expansion valve control device 81, and the second expansion valve control device 82 perform various calculations and processes according to the control program stored in the ROM to control the actions of various control target devices connected to the output side.

[0080] The first expansion valve control device 81 and the second expansion valve control device 82 are connected to each other via the air conditioning control device 80 and the wiring harness so as to be able to communicate with each other. Therefore, the operation of the control target device connected to the output side of the other control device can be controlled based on the detection signal or operation signal input to one control device.

[0081] The air conditioning control device 80 controls the operation of the compressor 111 of the vapor compression refrigeration cycle 110 , the electromagnetic on-off valve 117 , the blower 121 of the vehicle interior air conditioning unit 120 , the actuator for driving the air mix door 122 , and the like.

[0082] The first expansion valve control device 81 controls the operation of the first expansion valve 113 of the refrigeration cycle 110. Specifically, the value of the drive current output to the motor unit 11 of the first expansion valve control device 81 is calculated, and the drive current is output to the motor unit 11 according to the calculation result. The first expansion valve control device 81 is composed of the circuit unit 70 of the first expansion valve 113.

[0083] The second expansion valve control device 82 controls the operation of the second expansion valve 115 of the vapor compression refrigeration cycle 110. Specifically, the value of the drive current output to the motor unit 11 of the second expansion valve control device 82 is calculated, and the drive current is output to the motor unit 11 based on the calculation result. The second expansion valve control device 82 is formed by the circuit unit 70 of the second expansion valve 115.

[0084] The input side of the air conditioning control device 80 is connected to a control sensor group such as an indoor air temperature sensor 83, an outdoor air temperature sensor 84, a sunlight sensor 85, an air conditioning wind temperature sensor 86, a high-pressure side refrigerant sensor 87, and a low-pressure side refrigerant sensor 88. Detection signals of these sensors are input to the air conditioning control device 80. These sensors are included in the components constituting the refrigeration cycle.

[0085] The indoor air temperature sensor 83 is an indoor air temperature detection unit that detects the indoor air temperature Tr, which is the temperature inside the vehicle interior. The outdoor air temperature sensor 84 is an outdoor air temperature detection unit that detects the outdoor air temperature Tam, which is the temperature outside the vehicle interior. The sunshine sensor 85 is a sunshine amount detection unit that detects the sunshine amount As irradiated into the vehicle interior. The air conditioning wind temperature sensor 86 is an air conditioning wind temperature detection unit that detects the temperature TAV of the air conditioning wind sent from the vehicle interior air conditioning unit 120 into the vehicle interior.

[0086] The high-pressure refrigerant sensor 87 is a high-pressure refrigerant detection unit that detects the pressure and temperature of the high-pressure refrigerant in the vapor compression refrigeration cycle 110. The low-pressure refrigerant sensor 88 is a low-pressure refrigerant detection unit that detects the pressure and temperature of the low-pressure refrigerant in the vapor compression refrigeration cycle 110.

[0087] The input side of the air conditioning control device 80 is also connected to various operation switches provided on the air conditioning operation panel. The air conditioning operation panel is arranged near the instrument panel in the front part of the vehicle interior. The instrument panel is arranged near the front of the driver's seat in the front part of the vehicle interior. The instrument panel displays various information such as the driving speed of the electric vehicle and the operation status of the electric vehicle. When various devices of the electric vehicle are abnormal or fail, the instrument panel warns the passengers through display, sound, etc.

[0088] Operation signals from various operation switches of the air-conditioning operation panel are input to the air-conditioning control device 80. Specifically, various operation switches provided on the air-conditioning operation panel include an automatic switch, an air-conditioning switch, an air volume setting switch, a temperature setting switch, and the like.

[0089] The automatic switch is an operation unit for the passenger to set or release the automatic control driving of the air conditioner in the vehicle interior. The air conditioner switch is an operation unit for the passenger to request the cooling of the air by the indoor evaporator. The air volume setting switch is an operation unit for the passenger to manually set the air volume of the blower 121. The temperature setting switch is an operation unit for the passenger to set the set temperature Tset in the vehicle interior.

[0090] The input side of the first expansion valve control device 81 is connected to the first current and voltage sensor 90 and the first rotation angle sensor 91. The first current and voltage sensor 90 is a first expansion valve current and voltage detection unit that detects the current and voltage supplied to the motor unit 11 of the first expansion valve 113. The first rotation angle sensor 91 is a first rotation angle detection unit that detects the rotation angle (in other words, the rotation position) of the motor unit 11 of the first expansion valve 113.

[0091] The first current and voltage sensor 90 is attached to the first expansion valve 113. In the first current and voltage sensor 90, the current detection unit and the voltage detection unit are integrated, but the current detection unit and the voltage detection unit may be configured independently.

[0092] The input side of the second expansion valve control device 82 is connected to a second current and voltage sensor 92 and a second rotation angle sensor 93. The second current and voltage sensor 92 is a second expansion valve current and voltage detection unit that detects the current and voltage supplied to the motor unit 11 of the second expansion valve 115. The second rotation angle sensor 93 is a second rotation angle detection unit that detects the rotation angle (in other words, the rotation position) of the motor unit 11 of the second expansion valve 115.

[0093] The second current and voltage sensor 92 is attached to the second expansion valve 115. In the second current and voltage sensor 92, the current detection unit and the voltage detection unit are integrated, but the current detection unit and the voltage detection unit may be configured independently.

[0094] Next, the operation of the vehicle air conditioner 100 in the present embodiment will be described in general terms. The air conditioner control device 80 determines whether to execute any of the operation modes of the cooling mode, the heating mode, and the dehumidification heating mode based on detection signals from a control sensor group such as an indoor air temperature sensor 83, an outdoor air temperature sensor 84, a sunlight sensor 85, an air conditioning wind temperature sensor 86, a high-pressure side refrigerant sensor 87, and a low-pressure side refrigerant sensor 88.

[0095] The air conditioning control device 80 performs opening and closing control on the electromagnetic on-off valve 117 , the first expansion valve 113 , and the second expansion valve 115 , and switches to the determined operation mode.

[0096] In the cooling mode, the electromagnetic on-off valve 117 is in a closed state, the first expansion valve 113 is in a fully open state without throttling the refrigerant flow, and the second expansion valve 115 is in a valve opening degree that throttles the refrigerant flow. At this time, the air conditioning control device 80 determines the target throttling opening degree of the second expansion valve 115 based on the detection signal from the control sensor group, and outputs the determined target throttling opening degree to the second expansion valve control device 82. The second expansion valve control device 82 controls the second expansion valve 115 in such a way that the opening degree of the second expansion valve 115 becomes the target throttling opening degree output from the air conditioning control device 80.

[0097] In the heating mode, the electromagnetic on-off valve 117 is in an open state, the first expansion valve 113 is in a valve opening degree for throttling the flow of the refrigerant, and the second expansion valve 115 is in a closed state for blocking the flow of the refrigerant. At this time, the air conditioning control device 80 determines the target throttling opening degree of the first expansion valve 113 based on the detection signal from the control sensor group, and outputs the determined target throttling opening degree to the first expansion valve control device 81. The first expansion valve control device 81 controls the first expansion valve 113 in such a way that the opening degree of the first expansion valve 113 becomes the target throttling opening degree output from the air conditioning control device 80.

[0098] In the dehumidification heating mode, the electromagnetic on-off valve 117 is in the closed state, and the first expansion valve 113 and the second expansion valve 115 are in the valve opening degree for throttling the flow of the refrigerant. At this time, the air conditioning control device 80 determines the target throttling opening degree of the first expansion valve 113 and the target throttling opening degree of the second expansion valve 115 according to the detection signal from the control sensor group, and outputs the determined target throttling opening degree to the first expansion valve control device 81 and the second expansion valve control device 82.

[0099] The first expansion valve control device 81 controls the first expansion valve 113 so that the opening degree of the first expansion valve 113 becomes the target throttling opening degree output from the air conditioning control device 80. The second expansion valve control device 82 controls the second expansion valve 115 so that the opening degree of the second expansion valve 115 becomes the target throttling opening degree output from the air conditioning control device 80.

[0100] Next, the operation of the first expansion valve 113 in this embodiment will be described. The operation of the second expansion valve 115 is the same as that of the first expansion valve 113, and thus the description of the operation of the second expansion valve 115 will be omitted.

[0101] When the driving current is output from the first expansion valve control device 81 to the motor unit 11 of the first expansion valve 113, the rotor 13 of the motor unit 11 rotates, and the shaft 14 of the motor unit 11 also rotates integrally. When the shaft 14 of the motor unit 11 rotates and the drive side magnet 20 also rotates integrally, the magnetic pole piece 25 rotates in the same direction as the rotation direction of the drive side magnet 20 due to the interaction of the magnetic force between the drive side magnet 20 and the fixed magnet 40.

[0102] The reduction ratio at this time is equal to the value obtained by dividing the number of poles Pp of the pole piece 25 by the number of poles Pin of the drive side magnet 20. Since the number of poles Pp of the pole piece 25 is greater than the number of poles Pin of the drive side magnet 20, the rotation speed of the pole piece 25 is less than that of the drive side magnet 20.

[0103] In this example, the number of poles Pp of the pole piece 25 is 42, and the number of poles Pin of the driving side magnet 20 is 2, so the reduction ratio is 21.

[0104] On the other hand, in a configuration in which the pole piece 25 is fixed and a magnet having the same number of poles as the fixed magnet 40 is engaged with the rotating member 41 of the driven-side mechanism portion 35 for rotation (hereinafter referred to as a comparative example), the reduction ratio is 20.

[0105] Since the pole number Pp of the pole piece 25 is greater than the pole number Pf of the fixed magnet 40 , the reduction ratio in the present embodiment in which the pole piece 25 is rotated is greater than the reduction ratio in the comparative example in which a magnet having the same pole number as the fixed magnet 40 is rotated.

[0106] In the present embodiment where the pole piece 25 is rotated, the pole piece 25 is a separate member from the sealing plate 51. Therefore, the pressure resistance of the sealing plate 51 can be improved compared with the conventional structure where the pole piece is buried in the sealing plate without rotating.

[0107] The sealing plate 51 has the sealing cylindrical portion 51b and the sealing bottom surface portion 51c, and thus has a disk shape with the center portion recessed toward the driven-side mechanism portion 35. Therefore, the sealing plate 51 can be disposed as a separate component from the pole piece 25, and the pressure resistance of the sealing plate 51 can be improved.

[0108] The number Npp of the magnetic body portions 25a of the pole piece 25 is in the following relationship with respect to the number Pin of poles of the drive side magnet 20 and the number Pf of poles of the fixed magnet 40:

[0109] Npp=(Pin+Pf) / 2

[0110] Thus, the rotational force of the drive side magnet 20 can be transmitted to the magnetic pole piece 25. The rotational force of the drive side magnet 20 is transmitted to the magnetic pole piece 25, so that the rotating member 41 as the output shaft of the power transmission device 1 rotates, and the rotational force of the rotating member 41 is transmitted to the valve core 48, so that the valve core 48 moves in the axial direction. The valve core 48 moves in the axial direction, so that the valve port 52a of the valve chamber 52 is opened and closed, and the flow rate of the refrigerant passing through the valve port 52a is adjusted.

[0111] The first expansion valve control device 81 performs feedback control on the motor unit 11 based on the detection signals of the first current and voltage sensor 90 and the first rotation angle sensor 91. Figure 5 As shown, the torque generated by the motor unit 11 (hereinafter referred to as the motor torque) and the current supplied to the motor unit 11 (hereinafter referred to as the motor current) are in a proportional relationship.

[0112] The first expansion valve control device 81 stores in advance Figure 6 The fault detection current value Ib and the fully closed limit current value Is are shown. The fault detection current value Ib (in other words, the abnormality determination current value) is the current value corresponding to the fault detection torque value Tb. The fully closed limit current value Is is the current value corresponding to the fully closed limit torque value Ts.

[0113] The fault detection torque value Tb (in other words, the abnormality determination torque value) is the motor torque value when an abnormality occurs in the operation of the valve core 48. That is, the fault detection torque value Tb is the motor torque value when an abnormality occurs in the rotation of the motor part 11 due to interference of foreign matter in the valve core 48, and the motor torque increases sharply.

[0114] The fully closed limit torque value Ts is the value of the motor torque when the valve body 48 fully closes the valve port 52a. That is, the fully closed limit torque value Ts is the value of the motor torque when the valve body 48 is pressed by the valve seat 55 and the motor torque increases rapidly.

[0115] like Figure 6 As shown, the fault detection torque value Tb is greater than the maximum value Ta of the motor torque when the valve core 48 adjusts the opening of the valve port 52a to normal (in other words, during normal use) (hereinafter referred to as the torque value during opening adjustment), and is less than the basic speed torque value Tv of the motor unit 11 (hereinafter referred to as the basic speed torque value of the motor).

[0116] The motor unit 11 has a characteristic that the rotation speed of the motor unit 11 (hereinafter referred to as the motor rotation speed) is fixed relative to the motor torque within a range where the motor torque is less than the motor basic speed torque value Tv, and the motor rotation speed decreases as the motor torque increases within a range where the motor torque is greater than the motor basic speed torque value Tv.

[0117] Since the motor torque and the motor current are proportional as described above, the fault detection current value Ib is greater than the opening adjustment current value Ia and less than the motor basic speed current value Iv. The opening adjustment current value Ia is the current value corresponding to the opening adjustment torque value Ta. The motor basic speed current value Iv is the current value corresponding to the motor basic speed torque value Tv.

[0118] The fully closed limit torque value Ts is greater than the motor base speed torque value Tv and less than the magnetic gear imbalance torque value Tg. The magnetic gear imbalance torque value Tg is the minimum value of the motor torque at which the magnetic gear 60b is imbalanced.

[0119] Therefore, the fully closed limit current value Is is larger than the motor base speed current value Iv and smaller than the magnetic gear imbalance current value Ig. The magnetic gear imbalance current value Ig is a current value corresponding to the magnetic gear imbalance torque value Tg.

[0120] Figure 7 1000 is a flowchart showing the control process performed by the first expansion valve control device 81. In step S1000, an instruction signal for the operation mode of the first expansion valve 113 is input from the air conditioning control device 80. Specifically, an instruction signal for either the fully closed operation mode or the opening adjustment mode is input. The fully closed operation mode is an operation mode in which the first expansion valve 113 is fully closed. The opening adjustment mode is an operation mode in which the first expansion valve 113 is adjusted to a target opening.

[0121] In step S1010 , it is determined whether the operation mode instructed by the air conditioning control device 80 is the fully closed operation mode. If it is determined not to be the fully closed operation mode (that is, the opening adjustment mode), the process proceeds to step S1020 .

[0122] In step S1020, an instruction signal of a target opening degree is input from the air conditioning control device 80. In step S1030, a fault detection current value Ib pre-stored in the air conditioning control device 80 is read.

[0123] In step S1040 , feedback control is performed on the motor unit 11 so that the rotation position of the motor unit 11 approaches the target position.

[0124] In step S1050, fault detection control (in other words, abnormality determination control) is performed. Specifically, it is determined whether the motor current has reached the fault detection current value Ib based on the detection signal of the first current and voltage sensor 90. If it is determined in step S1050 that the motor current has not reached the fault detection current value Ib, the process proceeds to step S1060.

[0125] In step S1060, it is determined whether the rotation position of the motor unit 11 has reached the target position based on the detection signal of the first rotation angle sensor 91. If it is determined that the rotation position of the motor unit 11 has not reached the target position, the process returns to step S1040.

[0126] If it is determined in step S1060 that the rotation position of the motor portion 11 has reached the target position, the process proceeds to step 1070 , and a signal indicating that the motor portion 11 has reached the target position is output to the air conditioning control device 80 .

[0127] On the other hand, when it is determined in step S1050 that the motor current has reached the failure detection current value Ib, the process proceeds to step S1080 , and a signal indicating that the expansion valve is faulty is transmitted to the air conditioning control device 80 .

[0128] That is, since it is considered that the motor current is larger than the current value Ia during the opening adjustment due to interference of foreign matter, it is estimated that the first expansion valve 113 has a fault (in other words, an abnormality has occurred in the operation of the valve element 48).

[0129] On the other hand, when it is determined in step S1010 that the operation mode instructed by the air conditioning control device 80 is the fully closed operation mode, the process proceeds to step S1100 to read the fully closed time limit current value Is pre-stored in the air conditioning control device 80 .

[0130] In step S1110 , the motor unit 11 is feedback-controlled so that the rotation position of the motor unit 11 approaches the target position (the position at which the valve body 48 is fully closed).

[0131] In step S1120, it is determined whether the motor current has reached the fully closed limit current value Is based on the detection signal of the first current and voltage sensor 90. If it is determined in step S1120 that the motor current has not reached the fully closed limit current value Is, the process returns to step S1110.

[0132] When it is determined in step S1120 that the motor current has reached the fully closed limit current value Is, the process proceeds to step S1130 , and a signal indicating the completion of valve closing is output to the air conditioning control device 80 .

[0133] This can prevent the torque of the motor unit 11 from exceeding the magnetic gear detuning torque value Tg, thereby preventing the magnetic gear 60b from detuning and repeatedly rotating forward and reversely. As a result, the first expansion valve 113 can be fully closed reliably.

[0134] At this time, since the fully closed limit torque value Ts is greater than the motor basic speed torque value Tv, the first expansion valve 113 can be reliably fully closed by a large motor torque compared to the case where the fully closed limit torque value Ts is less than the motor basic speed torque value Tv.

[0135] Through the above control processing, a failure of the first expansion valve 113 can be detected when the valve core 48 adjusts the opening of the valve port 52a, and the valve port 52a can be reliably fully closed when the valve core 48 fully closes the valve port 52a.

[0136] Although the configuration in which the motor base speed torque value Tv is smaller than the magnetic gear out-of-step torque value Tg as in the present embodiment can reduce the size of the motor, there is a problem that the valve cannot be closed if the magnetic gear is out of step during the fully closed operation.

[0137] In this regard, in the present embodiment, by operating the motor unit 11 with current limitation during the full closing operation, reverse rotation due to the loss of synchronization of the magnetic gear 60 b can be prevented and full closing can be achieved reliably.

[0138] Furthermore, due to the characteristics of the magnetic gear 60b, the load torque gradually increases and decreases from the time of seating to the time of full closing, so that the sealing performance can be improved.

[0139] By not applying fault detection during full closing, refrigerant leakage can be reduced by tightening the valve core 48 with a motor torque suitable for closing after the valve core 48 is seated on the valve seat 55. Since the full closing limit current value Is is reached at the end of full closing, the end of full closing can be detected.

[0140] By applying fault detection during the flow rate adjustment operation, it is possible to detect a fault in which the output shaft of the motor unit 11 and the valve core 48 do not operate due to a foreign object blockage or the like by reaching the fault detection current value Ib. Therefore, it is possible to prevent the magnetic gear 60b from being misaligned due to the fault, thereby preventing a large change in the motor rotation speed due to the misalignment of the magnetic gear 60b, and further preventing a large vibration of the refrigerant piping.

[0141] In the present embodiment, the first expansion valve control device 81 limits the current supplied to the motor unit 11 to a fully closed limit current value Is or less during the fully closed state. The fully closed limit current value Is is a current value greater than the opening adjustment current value Ia.

[0142] This can prevent the motor current from becoming excessive and the magnetic gear 60b from becoming out of step during the fully closed operation. Therefore, the valve body 48 can be prevented from reversing due to the out of step of the magnetic gear 60b, thereby improving the fully closed property of the valve port 52a.

[0143] In the present embodiment, the fully closed time limit current value Is is a current value smaller than the magnetic gear out-of-step current value Ig. This can reliably suppress the magnetic gear 60b from being out of step during the fully closed operation.

[0144] In the present embodiment, the first expansion valve control device 81 performs fault detection control. In the fault detection control, if the current supplied to the motor unit 11 reaches the fault detection current value Ib, it is determined that the first expansion valve 113 has a fault. The fault detection current value Ib is a current value that is greater than the current value Ia during the opening adjustment and less than the limiting current value Is when fully closed. In this way, it is possible to detect that the first expansion valve 113 has a fault before the magnetic gear 60b is out of adjustment.

[0145] In the present embodiment, the failure detection current value Ib is a current value smaller than the magnetic gear out-of-step current value Ig. Thus, it is possible to reliably detect that the first expansion valve 113 has failed before the magnetic gear 60b becomes out of step.

[0146] In this embodiment, the current value Ia during the opening adjustment, the fault detection current value Ib, the fully closed limiting current value Is, and the magnetic gear misalignment current value Ig are in the relationship of Ia<Ib<Is<Ig. Thus, it is possible to reliably determine that the operation of the valve core 48 has an abnormality before the magnetic gear 60b is misaligned, and it is possible to reliably suppress the misalignment of the magnetic gear 60b during the fully closed operation.

[0147] In the present embodiment, the first expansion valve control device 81 does not perform failure detection control during the fully closed operation. This can avoid erroneous detection that a failure has occurred in the first expansion valve 113 when the valve element 48 closes the valve port 52a.

[0148] In the present embodiment, the fully closed time limit current value Is is a motor current value when the motor unit 11 becomes non-rotatable. This can reliably suppress the magnetic gear 60b from being out of step during the fully closed operation.

[0149] (Second Embodiment)

[0150] In the first embodiment, the opening adjustment current value Ia, the fault detection current value Ib, the motor basic speed current value Iv, the fully closed limit current value Is and the magnetic gear imbalance current value Ig are in the relationship of Ia<Ib<Iv<Is<Ig.

[0151] like Figure 8 As shown, in this embodiment, the current value Ia during opening adjustment, the fault detection current value Ib, the motor basic speed current value Iv, the fully closed limit current value Is and the magnetic gear imbalance current value Ig are in the relationship of Ia<Ib<Is<Iv<Ig.

[0152] Thus, since the valve can be rotated at the basic speed even when the valve is closed, the time until the valve is closed can be shortened compared to the first embodiment in which the valve is rotated at a speed lower than the basic speed when the valve is closed.

[0153] (Third Embodiment)

[0154] In the above-mentioned first embodiment, the current value Ia during opening adjustment, the fault detection current value Ib, the motor basic speed current value Iv, the fully closed limit current value Is and the magnetic gear imbalance current value Ig are in the relationship of Ia<Ib<Iv<Is<Ig.

[0155] like Fig. 9 As shown, in this embodiment, the current value Ia during opening adjustment, the fault detection current value Ib, the motor basic speed current value Iv, the fully closed limit current value Is and the magnetic gear imbalance current value Ig are in the relationship of Ia<Iv<Ib<Is<Ig.

[0156] As a result, the failure detection torque value Tb becomes larger than that of the first embodiment, and thus the flow rate adjustment operation can be performed with a larger torque than that of the first embodiment.

[0157] (Fourth Embodiment)

[0158] In the above-mentioned first embodiment, the current value Ia during opening adjustment, the fault detection current value Ib, the motor basic speed current value Iv, the fully closed limit current value Is and the magnetic gear imbalance current value Ig are in the relationship of Ia<Ib<Iv<Is<Ig.

[0159] Fig.10As shown, in this embodiment, the current value Ia during opening adjustment, the fault detection current value Ib, the motor basic speed current value Iv, the fully closed limit current value Is and the magnetic gear imbalance current value Ig are in the relationship of Ia<Iv<Ib=Is<Ig.

[0160] Thus, compared with the case where the failure detection torque value Tb and the fully closed limit torque value Ts are different from each other, the control can be simplified.

[0161] (Fifth Embodiment)

[0162] In the fault detection control of the above-mentioned first embodiment, when the current of the motor unit 11 reaches the fault detection current value Ib, it is determined that the first expansion valve 113 has a fault. However, in the fault detection control of the present embodiment, when the current of the motor unit 11 reaches the fault detection current value Ib and the motor unit 11 does not rotate, it is determined that the first expansion valve 113 has a fault.

[0163] Fig.11 1 is a flowchart showing the control process performed by the first expansion valve control device 81 of the present embodiment. In step S2000, an instruction signal of the operation mode is input from the air conditioning control device 80. In step S2010, it is determined whether the operation mode indicated by the air conditioning control device 80 is the fully closed operation mode. If it is determined that it is not the fully closed operation mode (i.e., the opening adjustment mode), the process proceeds to step S2020.

[0164] In step S2020, an instruction signal of a target opening is input from the air conditioning control device 80. In step S2030, a fault detection current value Ib pre-stored in the air conditioning control device 80 is read. In step S2040, the motor unit 11 is feedback-controlled so that the rotation position of the motor unit 11 approaches the target position.

[0165] In step S2050, it is determined whether the motor current has reached the fault detection current value Ib based on the detection signal of the first current and voltage sensor 90. If it is determined in step S2050 that the motor current has reached the fault detection current value Ib, the process proceeds to step S2060.

[0166] In step S2060, it is determined whether the motor unit 11 is rotating based on the detection signal of the first rotation angle sensor 91. If it is determined in step S2060 that the motor unit 11 is not rotating, the process proceeds to step S2070 and a signal indicating an expansion valve failure is sent to the air conditioning control device 80.

[0167] That is, since it can be considered that the interference of foreign matter or the like not only causes the motor current to be larger than the current value Ia during the opening adjustment but also makes the motor unit 11 unable to rotate, it is estimated that the first expansion valve 113 has failed.

[0168] If it is determined in step S2050 that the motor current has not reached the fault detection current value Ib, the process proceeds to step S2080. If it is determined in step S2060 that the motor unit 11 is rotating, the process proceeds to step S2080.

[0169] In step S2080, it is determined whether the rotation position of the motor unit 11 has reached the target position based on the detection signal of the first rotation angle sensor 91. If it is determined that the rotation position of the motor unit 11 has not reached the target position, the process returns to step S2040.

[0170] When it is determined in step S2080 that the rotation position of the motor portion 11 has reached the target position, the process proceeds to step S2090 , and a signal indicating that the motor portion 11 has reached the target position is output to the air conditioning control device 80 .

[0171] On the other hand, when it is determined in step S2010 that the operation mode instructed by the air conditioning control device 80 is the fully closed operation mode, the process proceeds to step S2100 to read the fully closed limit current value Is pre-stored in the air conditioning control device 80 .

[0172] In step S2110 , the motor unit 11 is feedback-controlled so that the rotation position of the motor unit 11 approaches the target position (the position at which the valve body 48 is fully closed).

[0173] In step S2120, it is determined whether the motor current has reached the fully closed limit current value Is based on the detection signal of the first current and voltage sensor 90. If it is determined in step S2120 that the motor current has not reached the fully closed limit current value Is, the process returns to step S2110.

[0174] When it is determined in step S2120 that the motor current has reached the fully closed limit current value Is, the process proceeds to step S2130 , and a signal indicating the completion of valve closing is output to the air conditioning control device 80 .

[0175] Thus, similarly to the above-described first embodiment, a failure of the first expansion valve 113 can be detected during the adjustment of the opening degree, and the valve port 52a can be reliably fully closed during the fully closing operation.

[0176] In the present embodiment, the first expansion valve control device 81 determines that a failure has occurred in the first expansion valve 113 when the motor current reaches the failure detection current value Ib and the motor unit 11 cannot rotate during the failure detection control.

[0177] Thus, it is possible to reliably detect that the first expansion valve 113 has failed before the magnetic gear 60 b becomes out of step.

[0178] (Sixth Embodiment)

[0179] In the fault detection control of the above-mentioned first embodiment, when the current of the motor unit 11 reaches the fault detection current value Ib, it is determined that the first expansion valve 113 has a fault. In the fault detection control of the present embodiment, when the motor unit 11 does not reach the target position within the specified time, it is determined that the first expansion valve 113 has a fault.

[0180] Fig.12 1 is a flowchart showing the control process performed by the first expansion valve control device 81 of the present embodiment. In step S3000, an instruction signal of the operation mode is input from the air conditioning control device 80. In step S3010, it is determined whether the operation mode indicated by the air conditioning control device 80 is the fully closed operation mode. If it is determined that it is not the fully closed operation mode (i.e., the opening adjustment mode), the process proceeds to step S3020.

[0181] In step S3020, an instruction signal of a target opening degree is input from the air conditioning control device 80. In step S3030, a fault detection current value Ib pre-stored in the air conditioning control device 80 is read.

[0182] In step S3040, the motor unit 11 is feedback-controlled so that the rotation position of the motor unit 11 approaches the target position. In step S3050, it is determined whether a predetermined time has passed since the motor unit 11 started rotating. If it is determined that the predetermined time has not passed since the motor unit 11 started rotating, the process returns to step S3040.

[0183] If it is determined in step S3050 that a predetermined time has passed since the motor unit 11 started rotating, the process proceeds to step S3060 to determine whether the rotation position of the motor unit 11 has reached the target position within the predetermined time based on the detection signal of the first rotation angle sensor 91 .

[0184] When it is determined in step S3060 that the rotation position of the motor portion 11 has reached the target position, the routine proceeds to step 3070 , and a signal indicating that the motor portion 11 has reached the target position is output to the air conditioning control device 80 .

[0185] If it is determined in step S3060 that the rotation position of the motor unit 11 has not reached the target position within the predetermined time, the process proceeds to step S3080 , and a signal indicating that the expansion valve is faulty is transmitted to the air conditioning control device 80 .

[0186] That is, it is considered that the interference of foreign matter or the like prevents the rotation position of the motor unit 11 from reaching the target position, and thus it is estimated that the first expansion valve 113 has failed.

[0187] On the other hand, when it is determined in step S3010 that the operation mode instructed by the air conditioning control device 80 is the fully closed operation mode, the process proceeds to step S3100, and the fully closed time limit current value Is pre-stored in the air conditioning control device 80 is read. In step S3110, the motor unit 11 is feedback-controlled so that the rotation position of the motor unit 11 approaches the target position (the position at which the valve core 48 is fully closed).

[0188] In step S3120, it is determined whether the motor current has reached the fully closed limit current value Is based on the detection signal of the first current and voltage sensor 90. If it is determined in step S3120 that the motor current has not reached the fully closed limit current value Is, the process returns to step S3110.

[0189] When it is determined in step S3120 that the motor current has reached the fully closed limit current value Is, the routine proceeds to step S3130 , and a signal indicating the completion of valve closing is output to the air conditioning control device 80 .

[0190] Thus, similarly to the above-described first embodiment, a failure of the first expansion valve 113 can be detected during the adjustment of the opening degree, and the valve port 52a can be reliably fully closed during the fully closing operation.

[0191] In the present embodiment, the first expansion valve control device 81 determines that a fault has occurred in the first expansion valve 113 when the motor current reaches the fault detection current value Ib and the motor unit 11 does not reach the target rotation position within a predetermined time during the fault detection control. The fault detection current value Ib is a current value that is greater than the current value Ia during the opening adjustment and less than the limiting current value Is during the full closing.

[0192] Thus, it is possible to reliably detect that the first expansion valve 113 has failed before the magnetic gear 60 b becomes out of step.

[0193] The present invention is not limited to the above-described embodiment, and various modifications may be made as described below without departing from the gist of the present invention.

[0194] In the above embodiment, an example in which the present invention is applied to an expansion valve of a vapor compression refrigeration cycle is shown, but the present invention is not limited to the expansion valve and can be applied to various electric valves that open and close a valve port through which a fluid passes by a valve element.

[0195] The present invention has been described based on the embodiments, but it should be understood that the present invention is not limited to the embodiments and structures. The present invention includes various modifications and variations within the scope of equality. In addition, various combinations and forms, and further combinations and forms containing only one element, above or below it, also fall within the scope and thought range of the present invention.

[0196] The features of the electric valve disclosed in this specification are as follows.

[0197] (Item 1)

[0198] An electric valve, comprising:

[0199] A motor unit (11) which generates a rotational driving force by being supplied with electric power;

[0200] A valve port forming member (50) which forms a valve port (52a) for fluid to pass through;

[0201] a valve core (48) which opens and closes the valve port;

[0202] a magnetic gear (60b) that magnetically transmits the rotational driving force from the output shaft (14) of the motor unit to the valve core; and

[0203] a control unit (81) for controlling a current supplied to the motor unit,

[0204] When the valve body performs a fully closing operation to fully close the valve port, the control unit limits the current supplied to the motor unit to a fully closed current limit value (Is) or less.

[0205] The fully closed time limiting current value is a current value greater than an opening adjustment current value (Ia), which is a value of current supplied to the motor unit during opening adjustment for adjusting the opening of the valve port through the valve element.

[0206] (Item 2)

[0207] In the electric valve described in item 1, the fully closed limit current value is a current value smaller than a magnetic gear misalignment current value (Ig), which is a current value when the magnetic gear is misaligned.

[0208] (Item 3)

[0209] In the electric valve according to item 1 or 2, when the current supplied to the electric motor reaches the abnormality determination current value (Ib), the control unit performs abnormality determination control to determine that an abnormality has occurred in the movement of the valve body,

[0210] The abnormality determination current value is a current value that is larger than the opening adjustment current value and smaller than the fully closed limit current value.

[0211] (Item 4)

[0212] In the electric valve according to item 1 or 2, when the current supplied to the motor unit reaches the abnormality determination current value (Ib) and the motor unit cannot rotate, the control unit performs abnormality determination control to determine that an abnormality has occurred in the movement of the valve core,

[0213] The abnormality determination current value is a current value that is larger than the opening adjustment current value and smaller than the fully closed limit current value.

[0214] (Item 5)

[0215] In the electric valve described in item 1 or 2, when the current supplied to the motor unit reaches the abnormality determination current value (Ib) and the motor unit does not reach the target rotation position within a prescribed time, the control unit performs abnormality determination control to determine that an abnormality has occurred in the movement of the valve core,

[0216] The abnormality determination current value is a current value that is larger than the opening adjustment current value and smaller than the fully closed limit current value.

[0217] (Item 6)

[0218] In the electric valve according to any one of items 3 to 5, the abnormality determination current value is a current value smaller than a magnetic gear imbalance current value (Ig) which is a current at which the magnetic gear becomes imbalanced.

[0219] (Item 7)

[0220] For the electric valve described in Item 6, when the current value during the opening adjustment is Ia, the abnormality judgment current value is Ib, the limiting current value when fully closed is Is, and the magnetic gear imbalance current value is Ig, the relationship is Ia<Ib<Is<Ig.

[0221] (Item 8)

[0222] In the electric valve described in Item 7, the control unit does not perform the abnormality determination control during the fully closing operation.

[0223] (Item 9)

[0224] The electric valve according to any one of items 1 to 8, wherein the control unit performs feedback control on a current supplied to the motor unit according to a rotational position of the motor unit,

[0225] The fully closed time limit current value is a current value supplied to the motor unit when the motor unit is unable to rotate.

Claims

1. An electric valve, characterized in that: have: A motor unit (11) which generates a rotational driving force by being supplied with electric power; A valve port forming member (50) which forms a valve port (52a) for fluid to pass through; a valve core (48) which opens and closes the valve port; a magnetic gear (60b) that magnetically transmits the rotational driving force from the output shaft (14) of the motor unit to the valve core; and a control unit (81) for controlling a current supplied to the motor unit, When the valve body performs a fully closing operation to fully close the valve port, the control unit limits the current supplied to the motor unit to a fully closed current limit value (Is) or less. The fully closed time limiting current value is a current value greater than an opening adjustment current value (Ia) which is a value of a current supplied to the motor unit during opening adjustment for adjusting the opening of the valve port through the valve element.

2. The electric valve according to claim 1, characterized in that: The fully closed time limiting current value is a current value that is smaller than a magnetic gear imbalance current value (Ig), and the magnetic gear imbalance current value is a current value when the magnetic gear is imbalanced.

3. The electric valve according to claim 1, characterized in that: When the current supplied to the motor unit reaches the abnormality determination current value (Ib), the control unit performs abnormality determination control to determine that an abnormality has occurred in the operation of the valve body, The abnormality determination current value is a current value that is larger than the opening adjustment current value and smaller than the fully closed limit current value.

4. The electric valve according to claim 1, characterized in that: When the current supplied to the motor unit reaches the abnormality determination current value (Ib) and the motor unit cannot rotate, the control unit performs abnormality determination control to determine that an abnormality has occurred in the movement of the valve body, The abnormality determination current value is a current value that is larger than the opening adjustment current value and smaller than the fully closed limit current value.

5. The electric valve according to claim 1, characterized in that: When the current supplied to the motor unit reaches the abnormality determination current value (Ib) and the motor unit does not reach the target rotation position within a predetermined time, the control unit performs abnormality determination control to determine that an abnormality has occurred in the movement of the valve element, The abnormality determination current value is a current value that is larger than the opening adjustment current value and smaller than the fully closed limit current value.

6. The electric valve according to any one of claims 3 to 5, characterized in that: The abnormality determination current value is a current value smaller than a magnetic gear out-of-step current value (Ig) which is a current at which the magnetic gear is out of step.

7. The electric valve according to claim 6, characterized in that: When the current value during the opening adjustment is Ia, the abnormality determination current value is Ib, the fully closed limiting current value is Is, and the magnetic gear imbalance current value is Ig, the relationship is Ia<Ib<Is<Ig.

8. The electric valve according to claim 7, characterized in that: The control unit does not perform the abnormality determination control during the fully closing operation.

9. The electric valve according to any one of claims 1 to 5, characterized in that: The control unit performs feedback control on a current supplied to the motor unit according to a rotational position of the motor unit. The fully closed time limit current value is a current value supplied to the motor unit when the motor unit is unable to rotate.

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